(66 days)
The MRII Cranial Drill and Accessories are intended to provide access through the skull for ventriculostomy or other neurological procedures, such as biopsy or catheter placement, in or near an MR scanner of 3T maximum strength. The MRII Cranial Drill and Accessories are intended to be used only when the scanner is not performing a scan. The MRII Cranial Drill is intended for single use only.
The MRII Cranial Drill and accessories is composed of the MR Compatible Hand Drill and Drill Bit Kits, packaged separately and found substantially equivalent in K 122456. The packaging is identical to that of the predicate device. The MRII Cranial Drill is wrapped in CSR and then sealed in a Tyvek pouch. The Drill Bit Kits are packaged in a sealed tray within a sealed Tyvek pouch.
The provided document, a 510(k) summary for the MRII Cranial Drill and Accessories, details performance data and a risk analysis to demonstrate substantial equivalence to a predicate device. It primarily focuses on the device's mechanical performance and safety within an MRI environment, rather than the performance of an AI algorithm or a diagnostic tool. Therefore, many of the requested fields related to AI performance, such as sample size for test sets, data provenance, number of experts for ground truth, adjudication method, MRMC studies, standalone performance with humans-in-the-loop, and training set information are not applicable to this device and document.
Here's a breakdown of the available information:
1. Table of Acceptance Criteria and Reported Device Performance
| Test | Acceptance Criteria | Reported Device Performance |
|---|---|---|
| Drilling Efficiency, Smooth Operation, and Vibration during Drilling | Drilling Efficiency: Drill through simulated material in under 1 minute. | |
| Smooth Operation and Vibration During Drilling: User evaluation score of 3.0 (scale of 1.0 - 5.0) or higher. | All modified MRI Hand Drills met the acceptance criteria. All Hand Drills were able to drill through the simulated material in under a minute and received user evaluation scores greater than 3.0 for both smooth operation and vibration during drilling. This was substantially equivalent to the predicate Hand Drill. | |
| Drill Bit Retention under Axial Loading, Drill Bit Loading, and Handling with Wet Gloves | Drill Bit Retention Under Axial Loading: 0 mm slippage under a 5.0 lbf minimum force. | |
| Drill Bit Loading, Wet Glove Usage: A user evaluation score of 3.0 (scale of 1.0 - 5.0) or higher. | All modified MRI Hand Drills met the acceptance criteria. None of the modified Hand Drills had any slippage when a minimum axial load of 5.0 lbf was applied in both tension and compression directions. The Drill Bit Loading and Wet Glove usage requirements both scored higher than 3.0 for all modified Hand Drills tested. This was substantially equivalent to the predicate Hand Drill. | |
| Drill Bit Retention under Torque Loading, Drill Bit Loading, and Handling with Wet Gloves | Drill Bit Retention Under Torque: No movement of the Drill Bit inside the Chuck Housing, when a Torque is applied to the Drill Bit. | |
| Drill Bit Loading, Wet Glove Usage: A user evaluation score of 3.0 (scale of 1.0 - 5.0) or higher. | All modified MRI Hand Drills met the acceptance criteria. None of the modified Hand Drills had any slippage when a minimum torque 10 in-lbf was applied to the Drill Bits. The Drill Bit Loading and Wet Glove usage requirements both scored higher than 3.0 for all modified Hand Drills tested. This was substantially equivalent to the predicate Hand Drill. | |
| MRI Hand Drill and Drill Bit Run-out Testing (new comparative test) | The modified Hand Drill shows a reduction in the amount of Run out in the Drill and Drill Bit. | All modified Hand Drills had approximately a 50% reduction in the amount of run-out (unwanted movement). This improvement does not change the use, safety or effectiveness of the Hand Drill. |
| MRI Hand Drill Shaft Deflection Test (new comparative test) | The modified MRI Hand Drills show a reduction in the amount of deflection in the shaft when a side load is applied to the Chuck assembly. | All modified MRI Hand Drills had a reduction in the amount of deflection by approximately 60%, compared to the PEEK shafts of the predicate Hand Drill. This improvement does not change the use, safety or effectiveness of the Hand Drill. |
| Chuck Housing Lock Washer Break Force Test (new test) | The Lock Washers shall have a minimum break force of 5 lbf. | All modified Hand Drills had a Lock Washer break force greater than 5.0 lbf. Predicate Hand Drills have not undergone this test, since they do not have a Lock Washer feature. This modification does not change the use, safety or effectiveness of the Hand Drill. |
| Chuck Tightening Torque vs. Chuck Insert Slip Torque (new comparative test) | No explicit numerical acceptance criteria is stated, but the goal is for the Chuck Insert not to slip at any tightening torque level. | The modified Hand Drill design did not slip at any level of Chuck tightening torque. The predicate Hand Drill Chuck Insert slip torque is approximately equal to the Chuck Housing's tightening torque. The user no longer has to tighten the chuck on the modified Hand Drill beyond what it takes to hold the drill bit. This modification does not change the use, safety or effectiveness. |
2. Sample size used for the test set and the data provenance
- Test Set Sample Size: The document does not specify exact numerical sample sizes for each test in terms of individual devices. It generally refers to "All modified MRI Hand Drills" or "Each Chuck/Shaft sub-assembly." For certain tests like "Drilling Efficiency," it mentions using 3.2, 4.5, and 6.0 mm Drill bits with "each Hand Drill Tested," implying multiple permutations.
- Data Provenance: The data is generated from in-house design verification testing conducted by the company (MRI Interventions, Inc.). This is prospective data from controlled experiments. The country of origin is not explicitly stated but can be inferred as the United States, given the FDA submission.
3. Number of experts used to establish the ground truth for the test set and the qualifications of those experts
- Not Applicable. This is a mechanical device performance study, not a medical imaging or diagnostic study requiring expert ground truth for interpretation. "User evaluation scores" are mentioned for "Smooth Operation and Vibration During Drilling," "Drill Bit Loading," and "Wet Glove usage," which implies subjective assessment by individuals, but their number and specific qualifications are not detailed beyond being users.
4. Adjudication method for the test set
- Not Applicable. As there is no expert consensus on ground truth, no adjudication method is relevant.
5. If a multi-reader multi-case (MRMC) comparative effectiveness study was done, If so, what was the effect size of how much human readers improve with AI vs without AI assistance
- Not Applicable. This is not an AI-powered diagnostic device, so an MRMC study comparing human readers with and without AI assistance is irrelevant.
6. If a standalone (i.e., algorithm only without human-in-the-loop performance) was done
- Not Applicable. This device does not involve an algorithm with standalone performance.
7. The type of ground truth used
- The "ground truth" for this device's performance is based on engineering specifications and measurable physical properties. For example, "0 mm slippage" for axial loading, "under 1 minute" for drilling efficiency, specific force and torque values, and reduction percentages for run-out and deflection. Some aspects involve "user evaluation scores" for subjective qualities like smooth operation and ease of handling.
8. The sample size for the training set
- Not Applicable. This is not an AI/machine learning device, so there is no training set. Design validation is based on physical testing and risk analysis.
9. How the ground truth for the training set was established
- Not Applicable. No training set exists.
§ 882.4300 Manual cranial drills, burrs, trephines, and their accessories
(a)
Identification. Manual cranial drills, burrs, trephines, and their accessories are bone cutting and drilling instruments that are used without a power source on a patient's skull.(b)
Classification. Class II (performance standards).